I've been through a couple. I don't have a computer science background and never took a data structures and algorithms class.
If you're like me and haven't taken one, there's a great course from Udacity for learning data structures and algorithms to pass technical interviews.
https://www.udacity.com/course/technical-interview--ud513
I completed this. I did additional practice on pramp.com and hackerrank.
Some of the most important tricks are being able to get the most efficient algorithm and being able to account for edge cases.
Some technical interviews will be live over the phone or in person. You will need to get good at talking out your thought process. Pramp.com is a great site to practice for that.
codility.com also has a nice set of tutorials to do for learning a number of different algorithms. I went through that and passed a codility coding screen with flying colors.